pydrizzle.exposure.Exposure

Class Exposure

This class will provide the basic functionality for keeping track of an exposure's parameters, including distortion model, WCS information, and metachip shape.

Instance Methods

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__init__(self, expname, handle=None, dqname=None, idckey=None, new=no, wcs=None, mask=None, pa_key=None, parity=None, idcdir=None, rot=None, extver=1, exptime=None, ref_pscale=1.0, binned=1, mt_wcs=None, group_indx=None)

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setCorners(self)
Initializes corners for the raw image.

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setSingleOffsets(self)
Computes the zero-point offset and shape of undistorted single chip relative to the full final output product metachip.

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getShape(self)
This method gets the shape after opening and reading the input image.

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setShape(self, size, pscale)
This method will set the shape for a new file if there is no image header information.

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buildCoeffsName(self)
Define the name of the coeffs file used for this chip.

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writeCoeffs(self)
Write out coeffs file for this chip.

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getDGEOExtn(self)
Builds filename with extension to access distortion correction image extension appropriate to each chip.

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getDGEOArrays(self)
Return numarray objects for the distortion correction image arrays.

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applyDeltaWCS(self, dcrval=None, dcrpix=None, drot=None, dscale=None)
Apply shifts to the WCS of this exposure.

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calcNewEdges(self, pscale=None)
This method will compute arrays for all the pixels around the edge of an image AFTER applying the geometry model.

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getWCS(self)

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showWCS(self)

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runDriz(self, pixfrac=1.0, kernel='turbo', fillval='INDEF')
Runs the 'drizzle' algorithm on this specific chip to create a numarray object of the undistorted image.

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getShape(self)

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This method gets the shape after opening and reading the input image. This version will be the default way of doing this, but each instrument may override this method with one specific to their data format.

setShape(self, size, pscale)

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This method will set the shape for a new file if there is no image header information.

Size will be defined as (nx,ny) and pixel size

getDGEOArrays(self)

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Return numarray objects for the distortion correction image arrays.

If no DGEOFILE is specified, it will return empty 2x2 arrays.

applyDeltaWCS(self, dcrval=None, dcrpix=None, drot=None, dscale=None)

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Apply shifts to the WCS of this exposure.

Shifts are always relative to the current value and in the same reference frame.

calcNewEdges(self, pscale=None)

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This method will compute arrays for all the pixels around
the edge of an image AFTER applying the geometry model.

Parameter: delta - offset from nominal crpix center position

Output:   xsides - array which contains the new positions for
                  all pixels along the LEFT and RIGHT edges
          ysides - array which contains the new positions for
                  all pixels along the TOP and BOTTOM edges
The new position for each pixel is calculated by calling
self.geometry.apply() on each position.

runDriz(self, pixfrac=1.0, kernel='turbo', fillval='INDEF')

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Runs the 'drizzle' algorithm on this specific chip to create a numarray object of the undistorted image.

The resulting drizzled image gets returned as a numarray object.